Margaret Cavendish (1623-1673)

Talk about a nimble brain! Cavendish was a multifaceted writer, who produced great works of science fiction, philosophy, poetry, and science. She was also a passionate animal rights advocate—one of the first in history—and insisted that science must not be morally compromised by animal testing. Plus, she was mad stylish: all your fashion geeks out there, take note of this beauty.